Archive for February, 2012

Who hasn’t opened a can of mixed nuts and found the Brazil nuts on top and the peanuts on the bottom? We’ll open one and look, today on Engineering Works!

It’s one of those universal experiences. Mixed nuts seem to un-mix themselves between the time they were packed and the time you open the can. It’s a question that begs for an answer. Fair warning: we don’t have one.

The phenomenon probably has implications for lots of things beyond nuts that unmix themselves. It affects all kinds of mixtures, dry cereal in boxes, for instance. Especially muesli, with its mixture of different-sized grains and flakes and nuts and fruit.

Researchers have demonstrated it with all kinds of things, down to beads of different sizes. You can do it yourself with a child’s beach bucket, some sand and rocks of different sizes. You’ll notice is that if you put the sand in first, the rocks sort of float on top of it. If you put the rocks in first, the sand slides into the open spaces between the rocks. And if you shake it enough, the sand ends up on the bottom. Always.

It’s easy to see – what’s – happening. But so far, it seems nobody has figured out why. It could be important. Think of all the things we use that depend on mixtures of solid things being the same all the way through.

We’re mixed up, too, so we’ll see you next time.

Engineering Works! is made possible by Texas A&M Engineering and produced by KAMU-FM in College Station. Learn more about engineering. Visit us on the World Wide Web.

We seem to be obsessed with high technology these days. Sometimes, low-tech works just as well. We’ll see what’s going on, today on Engineering Works!

High technology helps us do things that would have seemed miraculous only a few years ago. But sometimes, high tech doesn’t work. Consider the problem of keeping low birth weight infants alive. It’s a big one. Four million babies around the world die every year before they’re a month old. Mostly because they were really little when they were born, or they were born early.

One of the most effective ways to help is simply to keep them warm. In modern hospitals, that’s no problem. We have high-tech incubators to do the job. In much of the world, though, these $40,000, high-tech machines are out of reach. Too expensive. And too hard to keep running.

Designers have come up with a deliberately low-tech incubator. It’ll work almost anywhere there are old cars. It’s really simple. The heat comes from old automobile headlights. Air circulation from dashboard fans. Door chimes are alarms. And they’re powered by batteries from that same car. You can find old car parts just about everywhere, even in remote villages in Africa or South America. And the people who know how to fix them or put their parts together into incubators. The same idea works for other needs we meet with high technology.

Our high tech is working fine, but we’re still done for today. See you next time. Engineering Works! is made possible by Texas A&M Engineering and produced by KAMU-FM in College Station. Learn more about engineering. Visit us on the World Wide Web.

Start the discussion: We’re so used to the wonders of high technology that we often ignore the need for lower tech alternatives that work. Incubators are only one example. What other low tech solutions have you seen?

Half a century ago, a pioneering computer researcher made a rash prediction. We’ll see how that’s working out, today on Engineering Works!

The researcher’s name is Gordon Moore. In 1965, he was director of research and development at the Fairchild Semiconductor Corporation. He predicted that the number of transistors that could be fit onto a computer chip would double about every two years. He thought that by 1975, as many as 65,000 transistors might be crowded onto a chip the size of a pencil eraser. And this might lead to computers so small some of us would have them at home.

Lots of people thought he was wrong and told him so. In 1965, fitting 50 transistors onto a chip was a big deal. Moore didn’t let the criticism bother him and he went on to do other things, like co-founding the Intel Corporation. His prediction became known as Moore’s Law. It still works. These days, chips with 500-million transistors are nothing unusual.

Lately, researchers have begun to worry that we may be getting to the end of Moore’s Law. Computer components will get so small that the strange laws of quantum mechanics will make transistors stop working. Computer chips will be as small as they can ever be.

Moore’s law seems to be safe for awhile yet. New research suggests we can still keep shrinking the size of computers without breaking Moore’s law.

Our law says we’re out of time for now. See you next time.

Engineering Works! is made possible by Texas A&M Engineering and produced by KAMU-FM in College Station. Learn more about engineering. Visit us on the World Wide Web.

Biomedical engineers in Washington State are come up with a way to build synthetic substitutes for bone fragments that could be fit into shattered bones to help them heal.

The new bone begins with a digital CT scan of the bone fragment that needs to be replaced. That scan is converted to a computer-assisted design, or CAD, file that controls a commercially available three-dimensional printer. The printer follows the CAD file’s digital instructions to stack 20-micron-thick layers of powder stabilized with a special plastic into the shape needed.

The powder is a mixture of calcium phosphate, silicon and zinc. The cool part is that after a while, natural bone cells replace this synthetic scaffold, and you end up with a whole bone again.

The researchers think that in addition to repairing badly broken bones, the idea also could be used in dental repairs and to deliver medications to treat osteoporosis. They’ve tested it on laboratory animals, and so far it seems to work the way they expected it to.

It will be awhile before your surgeon will be using it to fix that broken leg, but it’s on the way.

Our bones are fine, so we’re going to stand up and walk out the door. See you next time.

Engineering Works! is made possible by Texas A&M Engineering and produced by KAMU-FM in College Station. Learn more about engineering. Visit us on the World Wide Web.